Strap tightener



Oct. 13, 1931.

W. KITJEHNER STRAP TIGHTENER Filed Sept. 2, 1930 Patented ct. '13, 1931 PATENT OFI-Ica WILHELM KUEHNEB, OFPMVIDENCE, RHODE ISLAND STRAP TIGHTEN B1B Application Med September 2, 1930. Serial No. 479,286.

My invention relates to strap tighteners of atype adapted to be inserted in a stra for expanding or contractingthe len h o the strap and of a type having a mem r resiliently slidable relative to the rest of the strap tightener. Y

My invention is particularly adapted for use with wrist watch bracelet straps although it is obvious that if desired it may be used for other purposes. It is commonly used in f vide a slidable member or connector section of l what is known in the trade as a centerfold, namely at a point in the bracelet op osite the wrist watch, but it is obvious that 1t may be used on other points of the bracelet, namely adjacent the wrist watch if desired.

My invention is particularly adapted to form a iexible strap tightener so that where employed in a wrist watch bracelet the length of the strap will automatically conform to the strains on and the configuration of the wrist or other limb or member on which it may be employed. Employing an expansible strap tightener of this description it is obvious that it will not-be necessary to take out chain links where a chain is em loyed or shorten the end ofthe strap to fit di erent sized'vrists or other members.

A further object of the strap tightener of the type shown herein is that it automatically tends to hold the watchin the desired sition on top of the middle of the wrist. t is apparent from an inspection of mydevice that the strap tightener is of the type ca able of opening upto permit removal of t e strap from the wrist and adapted when in closed position to fiexibly and rmly clasp thestra to the wrist so that the strap will be boun to the wrist without inconvenience during all movements of the arm and wrist. l

A further feature of my invention relates in the specic means I employ to connect the connector sectionstogether. I provide preferably a separate tubular extension projecting from one connector section which 1s resilient and which is adapted toresiliently fit into a cooperating slot in a superimposed connector section. While I preferably form my device of three connector sections to give the desired length to open up the. strap tightener suiciently to remove the strap from the wrist, I

preferably construct the other connector secl vthe connector section having the opening extension is brought substantially adj aeent thereto.

A further feature of my invention is to prothis description, particularly adapted for use 4with open links which are now coming into vogue, which links are preferably uare or rectangular and to this end I preferab y shape the slidable member of open square or rectangular shape so that when said slidable member is in extended ositionit will simulate and look like an adjacent connected link. A further feature of my invention relates to the provision of a strap tightener of this descri tion made of a minimum number of wor ngparts which is strong, compact, neat in appearance and which may be readily put together.

These and such other objects of my invention as may hereinafter appear will be best understood from a descriptlon of the accompanying drawin which illustrate an emodlment thereo attached to an open square link chain.

In the drawings, Fig. 1 is a plan view of my im roved strap tightenerwiththe adjacent en s of such a chain attached thereto in closed position.

Fig. 2 is a perspective view of the strap ti htener and adjacent chain end shown in F1g.- 1 with the strap'tightener in open position.

Fig. 3 'is a plan view generally similar to Fig. 1 with the ltop plate of the top connector section removedl to show the construction of the interior of the top connector section and the means for clamping the intermediate and back connector sections together.

Fig. 4 is a longitudinal sectional view taken along the line 4-11 of Fig. 3.

Fig. 5 is a transverse sectional view taken along the line 5--5 of Fig. 4.

In the drawings, wherein like characters 'iii of reference indicate like parts throughout, generally indicates a strap tightener constructed in accordance with the principles of my invention shown employed as a centerfold of a wrist watch bracelet strap. v

In the description and claims, except as otherwise stated, I employ the words inner and outer in reference'to the end of the back connector section having the strap end hinged thereto when said members are in open positions. Said strap tightener com'- prises a back connector section 12 having means such as the struck up lugs 14 at the inner end thereof ada ted to receive a pivot bar 16 havi suita le means projecting therefrom suc as the links 18 to attach the adjacent end of an open square or rectangular block link chain fabric20 thereto. Although I have shown my invention attached to a block link chain fabric, itis obvious that any suitable type of strap may be employed and any suitable means to attach a strap end to the inner end of the back connector section may be emplo ed. The intermediate connector section 22 as its inner end hinged to the outer end of the back connector section 12 by any suitable means such as the hinge/ 24. The front connector section 26 is hinged to the outer end of the intermediate connector section 22 by means of the hinge 28 and is provided with suitable means later to be described in detail to resiliently attach an opposite strap end 32 thereto, referabl to the slidable member 34 thereo It is o vious that when in closed position said intermediate connector section 22 and front connector section 26 are adapted to overlie respectively said back and intermediate connector sections.

I provide means to detachably secure said intermediate connector section 22 to said back connector section l2 to secure all three connector sections together in closed position. For this purpose, I preferably provide the upper surface of the back connector section 12 with two resilient projections 36 extending upwards therefrom and the intermediate connector section 22 with two cooperating slots 38 therein adapted to receivel said projections 36 to resiliently retain said connector sections in closed position, in the embodiment shown said slots 38 and projections 36 being relativelyl near thev inner end of said section when they are in closed osition. The back' connector section 12 pre erabl comprises a plate preferably stam ed or ot erwise fabricated of flat stock an the two substantially tubular resilient rolled over projections 36 preferably consistin of separate members struck up through t e plate and the intermediate connector section 22 also preferabl comprises a plate. For the purposes of ad ing strength to the intermediate connector section 22 and back connector section 12, and to keep them in alignment, I preferably procooperating grooves 42 sunk in t e upper sur- 5 face of the back connector section 12.

In my preferred embodiment, the front connector section 26 is preferably constructedv as follows: I provide the top plate 44 having the downwardl projecting side walls 46. I preferably exten the inner end of the top wall as at 48 to provide an o ning extension for the strap tightener an also to prevent superimposing of the intermediate connector section 22 on the back connector section 12 to permit the projections 36 from the back connector section 12 from fitting into the slots 38 in the intermediate connector section until the front connector section 26 is superimposed on the intermediate connector section 22. To provide an expansible top connector.

section, l provide a slidable member 34 adapted to slide underneath said top plate 44 having suitable means at the outer end thereof for hingedly securing` a. chain or strap end 32 thereto. As stated, in my embodiment, said slidable member is preferably an open 'rectangular member so that when in extended osition it may simulate one of the links of t e open block chain. To

secure said slidable member 34 underneath' said top plate, I rovide the back plate 47 having an upstan ing outer wall 50 preferably open as at 52 near each end thereof for passage of the sides 35 of the rectangular slidable member therethrough and I provide means to secure said back plate 47' within saidto plate 44. Any means may be rovided erred embodiment I provide the back plate with the upstanding side walls 54 adapted to be frictionally retained Within the side walls 46 of the top plate 44.` To normally urge the rectangular slidable member 34 inwards I provide spring means such as the flat spring 58 shown, having the outer end thereof slidable member 34. The inner end 70 of the slidable member may be extended if desired a substantial distance beyond the spring and may have its center portion cut away as at 72 1n order to provide space for the u standing resilient projections 36 after they ave passed through the slots 38v to compactl lie within.

It is obvious that in practice the spring 58 will normally urge the rectangular member inwards within the top connector section 26, but will freely contract to permit the desired expansion of the chain or stra on outward movement of said slidable mem er.

rI`lhe operation of my invention is obvious from the above description; It is merely referred A.

or this purpose and in the pre-` necessary to open up the connector sections to the open osition shown in Fig. 2 to insert the wrist t rough the expanded chain or strap andwhen the strap has been placed in 5 the desired position on the wrist the three connector sections are superimposed respectively one on top of the other the o ening extension 48 preventing the back an intermediate connector sections from locking'together until the top connector section 26 is superimposed thereon. As the sections are brought into superimposed relationship it is obvious that the resilient tubular projections 36 will slide through the slots 38 to compactly secure all three sections together. It is obvious that as the wrist'or limb ex ands' or moves in use the strap end 32 an connected slidable member 34 will loosely slide within the top connector 26- to permit this freedom o'f movement. i To detach from the wrist itis merely necessary to insert av thumb nail or other sharp instrument under the opening extension 48 when the resiliently tubular projections 36 will sna vout of the slots 38 to permit the strap tig tener to expand to the position shown in Fig. 2.

lnorder that the entire strap tightener maybe compact, the backconnector section 12 is made slightly longer than the others and the various connector sections are made of such a length that when in closed position the hinge means 24 for joinin the back and intermediate connector sections together will extend beyond the outer wall 50 of the back plate of the front connector section and lie 34 thereof, the hinge means 16 for joining the inner end of the back connector section and chain end 20 and the hinge means 28 for section and the outer end of the intermediate connector section will lie intermediate said top and bottom connector sections and the opening extension 48 of the front connector section top plate will project inwardly of said hinge means and back connector section to permit the ready operation thereof.

lt is thus obvious that l have provided a strap tightener of a compact and neat form of a minimum number of working parts. As also stated while my invention is particularly adapted for use with openilink chains and the slidable member 34 is made to simulate one of these chains in use it is obvious that for certain features of my invention any type ot strap ends may be attached thereto.

As shown the connector sections maybe made of arcuate form to morecompactly conform to the shape of the wrist orlimb.

lt is understood that my invention is not limited to the specific embodiment shown and that various deviations may be made therefrom without departing from the spirit and c: scope ofthe appended claims.

underneath the slidable rectangular member joining the inner end of the front connector What I claim isi-- chain consistingof substantially s uare or rectangularl open links for expan ing or f contracting the length of thel chain, consisting of a back connector section comprising a pla-te having two resilient rolled over substantially tubular projections projectin therefrom near the inner. end thereof an hinge means at the inner end thereof for securing a chain end thereto, an intermediate connector section comprising a plate having two cooperating slots therein near the outer end thereof adapted to receive said tubular projections to secure said connector sections to lther when said intermediate connector sectlon is brought into closed position overlying said back connector section, a front connector section comprising a to plate havingI downwardly projecting si es and an .opening extension at the inner end thereof, an open rectangular member slidable within said to late having means at the outer end thereofpibr hingedly securing a chain end thereto whereby when in extended position said rectangular member may simulate a chain link, a back plate having an upstanding outer wall o en at each side thereof for passage of the sidlds of the rectangular member therethrough, means abutting the outer wall of the back plate and the outer edge of the inner wall of the rectangular member to normally urge said member inwardly and means to secure said back plate within said top plate, hinge means to secure the outer end of the back connector section to the inner end of the intermediate connector section, and means to eoA secure the outer end of said intermediate connector section to the inner' end of said front connector section top plate, the sections being of such lengths that when in closed position the hinge means for joining the bach and intermediate connector sections will extend beyond the outer wall of the back plate of the top connector section and lie underneath the slidable rectangular member thereof, rthe hinge means for joining the inner end of the back connector section and chain end and the hinge means tor joining the top connector section and intermedia-te connector section will lie intermediate said top and bottom connector sections and the opening extension of the front connector section top plate will pro'ect inwardly of said hinge means and bac connector section and prevent attachment of said bach and intermediate connector sections until the top section also overlies j chain consisting of substantially square or rectangular open links for expanding or contracting the length of the chain, consisting of a back connector section having hinge means at the inner end thereof for securing a chain end thereto, .an intermediate `connector section,A means `to secure connector sections together when' said intermediate connector section is brought in closed position overlying said back connector sections, a-front c ona nector section comprising 'a top ilate having downwardlyprojecting sides an an opening extension at the inner end thereof, an open yrectangular member'slidable within said top late havin means-atthe outer end thereof or hinge y securing a chain end thereto whereby when in extended position .said rectan lar member may simulate a cham link, a bacuplate having an lupstanding outer wall open at. each side thereof for passage of the sides of the rectangular member. therethrough, means abutting the outer wallof the back plate and the outer edge of the inner wall of such lengths that when in closed position the hinge means for joining the back and intermediate connector sections will extend beyond the outer wall of the back late of the top connector section and lie un erneathv the slide-ble rectangular member thereof, the hinge means for joinin the inner end of the back connector section and chain end and the hinge means for joining the top connector section and intermediate connector sectionwilll lie intermediate said top and bottom connector sections and the opening extension of the front connector section top plate will, ro'ect inwardly of said hinge means and c connector section and pre- 'vent attachment of said back and intermediate connector sections until the top section also overlies them.

3. A tightener adapted to be inserted in a chain consisting of substantially square or rectangular open links for expanding or contracting the length of the chain, consisting of a back connector section having hinge means at the inner end thereof for securing ing outer wall open at each si e thereof-for marina y assage ofthe sidesof the rectangular mentv er therethrou h, means' abutting the outer wall of the bac plate and the outer edge ofl the inner wall of the rectangular member to normally urge said member inwardl and means tosecure saidbackplate within said tofp 1plate, hinge means to secure the outer end o t eback connector section to the inner end of the intermediate connector section` and hinge'means to secure the outer end of said intermediate connector section to the inner end of said front connector section top late.

4. A tightener adapted to be inse in a stra for expanding or contracting the length of t e strap, consisting of a back connector section coiprising a plate having two resilient roll over substantially tubular projections projecting therefrom near the inner end thereof vand hinge means at the inner end thereof for securing a strap end thereto, an intermediate connector section comprising a plate having two cooperating slots therein near the outer end thereof adapted to receive said tubularprojections to secure said connector sections together when said intermediate connector section is brought into closed position overlying said back connector section, a front connector section comprising a to plate having downwardly projecting si es 'and an opening extension at the inner end thereof, an o n member slidable within said top late aving means at the outer end thereof. or hingedly securing a strap end thereto, a back plate having an upstanding outer wall having an open portion for passage of the slidable member therethrough, means abutting the outer wall of the back plate and the outer edge of the inner Wall of the open slidable member to normally urge said member inwardly, and. means to secure said back plate within said top plate, hinge means to secure the outer end of the back connector section to the inner end of the intermediate connector section, and hinge means to secure the outer end of said intermediate connector section to the inner end of said front connector section top plate, the sectionsbeing of such lengths that when in closed position the hinge means -for joining the back and intermediate connector sections will extend beyond the outer wall of the back plate of the top connector section and lie underneath the slidable member thereof, the hinge means for joining the inner end of the back connector section and strap end and the hinge means for joining the top connector section and intermediate connector section will lie intermediate said top and bottom connector sections and the opening extension of the front connector section top plate will project inwardly of said hinge means and back connector section and prevent attachment of said back and intermediate connector sections until the top section also overlies them.

5. A. tightener adapted to be inserted in a veo strap for expanding or contracting the length of the strap consisting of a back connector section having hinge means at the inner end thereof for'securing a strap end thereto, an intermediate connector section, means to secure said connector sections together when said intermediate connector section is brought into closed position overlying said back connector section, a front connector comprising a top plate having downwardly projecting sides and an opening extension at the inner end thereof, an open member slidable within said top plate having means at the outer end thereof for hingedly securing'aI strap end thereto, a back plate having an upstanding outer wall having open portions for passage of the sides of the slidable member therethrough, means abutting the outer wall of the back plate and the outer edge ofthe inner wall of the slidable member to normally urge said member inwardly, and means to secure said back plate Within said top plate, hinge means to secure the outer end of the back connector section to the inner end of the intermediate connector section, and hinge means to secure the outer end of said intermediate connector section to the inner end of said front connector section top plate, the sections being of such lengths that when in closed position the hinge means for joining the back and intermediate connector sectionsY will extend beyond the outer Wall of the back plate of the top connector section and lie underneath the slidable member thereof, the hinge means for joining the inner end of the back connector section and strap end and the hinge means for joining the top connector Vsection and intermediate connector section will lie intermediate said top and bottom connector sections and the opening extension of the front connector section top plate will project inwardly of said hinge means and back connector section and prevent attachment of said back and intermediate connector sections until thel top section also overlies them.

6. A tightener adapted to be inserted in a stra for expanding or contracting the length of t e strap, consisting of a bac connector section havmg hinge means at the inner end thereof for securing a strap end thereto, an intermediate connector section, means to secure said connector sections together when said intermediate connector section is brought into closed position overlying said back connector section, a front connector comprising a top plate having downwardly projecting sides and an opemng extension at the inner end thereof, an open member adapted to slide within said top plate having means at the outer end thereof for securing a strap end thereto, a back plate having an upstanding vao outer wall having open portions for passage of the sides of the slidable member therethrough, means abutting the outer wall of the back plate and the outer edge of the inner 

